Perceived annoyance from environmental odors and association with atmospheric ammonia levels in non-urban residential communities: a cross-sectional study

A cross-sectional study where NH3 concentration was obtained from the national air quality monitoring program and from emission-dispersion modelling, and odor pollution perception from questionnaires. The exposure-response model was a sigmoid model. Linear regression analyses were used to estimate the model constants after equation transformations. The model was validated using leave-one-out cross validation (LOOCV) statistical method.About 45% of the respondents were annoyed by odor pollution at their residential areas. The perceived odor was characterized by all respondents as animal waste odor. The exposure-annoyance sigmoid model showed that the prevalence of odor annoyance was significantly associated with NH3 concentrations (measured and estimated) at the local air quality monitoring stations (p？<？0.01,R2？=？0.99; and p？<？0.05,R2？=？0.93; respectively). Prediction errors were below 5.1% and 20% respectively. The seasonal pattern of odor perception was associated with the seasonal variation in NH3 concentrations (p？<？0.001, adjusted R2？=？0.68).The results suggest that atmospheric NH3 levels at local air quality stations could be used as indicators of prevalence of odor annoyance in non-urban residential communities.Odor is an environmental pollutant that can impose physical, psychological, social and behavioral stress to humans. As a result, exposure to outdoor malodor in residential areas can cause negative public reactions and complaints from the citizens. Annoyance is the first negative reaction reported by humans exposed to increasing concentrations of environmental malodor, and it has been pointed out as an important component of an early warning system of health impairment [1]. Annoyance can be defined as “a feeling of displeasure associated with any agent or condition, known or believed by an individual or group to adversely affect them” [2]. People annoyed by odor may also report respiratory symptoms and health impairment even at odorant exposures below i